增加 silence 方式

[hustcc]

[中级任务]

参考 batch 的方式，batch 是批量处理多个数据 API，只抛出一次 changes；silence 是处理数据后不抛出任何的 changes，两者都是对性能进行优化。

batch

Batch several graph changes into one. Make several changes, but dispatch only one ChangedEvent at the end of batch:

graph.batch(() => {
  graph.addNodes([]);
  graph.addEdges([]);
});

silence

DO NOT dispatch any changes.

graph.silence(() => {
  graph.addNodes([]);
  graph.addEdges([]);
});